1. Technical Field
The present invention relates to a micropump formed by detachably coupling a pump module and a drive module.
2. Related Art
In the related art, a small peristaltic pump device including a pump module having a tube and a rotor pressing the tube and a motor module having a step motor and an output gear mechanism stacked and assembled, a gear as a linking element provided on a rotational shaft of the rotor, and a pinion as a power take-off mechanism provided in the output gear mechanism is known. When the pump module and the motor module are stacked and linked, the pinion and the gear are linked (meshed) and the drive force of the step motor is transmitted to the rotor (e.g., see Japanese Patent No. 3177742 (page 3, FIGS. 1 and 3).
In Japanese Patent No. 3177742, linkage of the drive force of the pump module and the motor module is made by meshing the pinion at the pump module side and the gear at the motor module side. However, when the pump module and the motor module are stacked and assembled, if the teeth of the pinion and the gear are out of phase with each other, it is conceivable that the pinion and the gear overlap each other and the pinion or gear may be broken. Further, even if it is not broken, there may be a problem that the step motor can not be driven due to overload.
Further, the step motor is contained in the motor module. In Japanese Patent No. 3177742, a structure adopting a step motor for watch is taken as an example. In the step motor, dimensions of the component elements are very small, and it is predicted that the durability can not be secured due to the load when the pump module is driven. The small peristaltic pump device is principally used for directly attaching to a human body for injection of a chemical solution, and therefore, the reliability and durability in driving of the step motor are important.
In this application, it is desirable that the motor module in no direct contact with the chemical solution is repeatedly used and the pump module for flowing the chemical solution is disposable. For the same reason, it is also desirable that the step motor is replaced after a predetermined period of driving. However, since the step motor is incorporated in the motor module, i.e., the watch movement, the step motor is not easily removed without a special technique.
Furthermore, if the pump module and the motor module are not properly assembled, there may be problems that the pinion and the gear are broken and the step motor can not be driven as described above. Therefore, a detection device for detecting whether or not they are properly assembled before driving is required.